Field of the Invention
The invention relates to the technical field of semiconductor production, in particular to a production process for high-purity silicon carbide used as the substrate material of semiconductor devices.
Background of the Invention
The current production process for silicon carbide mixes the silica and the carbon source in proportion, and then heating them with an Acheson furnace. The carbon sources refer to petroleum coke, resin, asphalt, graphite, carbon fiber, coal, charcoal, etc. which contains the carbon element. The silicon dioxide in the silica reacts with the carbon in the carbon source and forms silicon carbide; however, there are lots of metallic impurities in these silica and carbon sources. In a high temperature environment, these impurities also chemically react, affecting the purity of the silicon carbide significantly. The purity of silicon carbide is reduced and it cannot meet the market demand for high-purity silicon carbide. Also, the exhaust produced by the reaction causes serious pollution to the environment. The current production processes have a lot of issues that urgently need resolutions.
In addition, previously, silicon carbide was produced with simple equipment. This kind of simple and outdoor equipment produces plenty of low-purity silicon carbide, tragically pollutes the environment. The cheap silicon carbide does not conform to the environmental regulations, and also can't meet the market demand.